是否

• Pinyin: shì fǒu
• Hanzi breakdown: 是 = 日 (sun) + 疋 (foot), originally meaning correct or right; 否 = 不 (not) + 口 (mouth), meaning to deny

Meaning

Whether or not; if. A formal way to ask about or state a yes/no condition.

A formal equivalent of 是不是, used in written Chinese, official documents, news reports, and formal speech. Introduces a yes/no question or condition. Much more formal than spoken alternatives.

Examples

1. 请确认一下您是否已经收到了邮件。 Please confirm whether you have received the email.
2. 他还在考虑是否要换工作。 He is still considering whether to change jobs.
3. 这个方案是否可行，还需要进一步讨论。 Whether this plan is feasible still needs further discussion.

Usage Guide

Context: writing, business, official

Tone: polite

Do Say

• 我想了解一下这个活动是否还有名额。(I would like to know whether there are still spots available for this event.)
• 请问您是否需要帮助？(May I ask whether you need help?)

Don't Say

• 你是否要吃饭？(Don't use 是否 in casual conversation with friends — it sounds overly formal; use 你要不要吃饭 instead.)

Origin & History

Compound of 是 (to be, yes) and 否 (not, no), literally 'yes or no' — a classical Chinese construction.

Cultural Context

Generation: All ages

Social background: Universal